A washing machine generally refers to various devices for processing the laundry by applying a physical and chemical action to the laundry, such as a laundry machine for detaching a contaminant from the clothes, bedclothes, and the like, (referred to as the ‘laundry’, hereinafter) by using a chemical decomposition operation between water and a detergent and a physical operation such as friction between water and the laundry.
The related art washing machine includes a pulsator that is rotatably provided in an inner tub in which laundry is loaded. The inner tub and/or pulsator rotate by a motor. Here, rotational force generated by the motor is selectively transferred to the inner tub and/or pulsator by a clutch.
The clutch moves up and down by buoyancy created by the wash water. When the clutch is in an upper position, a driving shaft of the motor is engaged with the pulsator to rotate only the pulsator. When the clutch is in a lower position, the driving shaft of the motor is engaged with both the pulsator and inner tub to rotate the pulsator and inner tub together.
However, the clutch that operates by the buoyancy has a problem in that, since it is always in the upper position when the wash water is filled in the inner tub, it cannot rotate the inner tub when the wash water is filled in the inner tub. When the wash water is filled in the inner tub, the prior art buoyancy clutch can rotate only the pulsator. That is, the clutch is engaged with not only the pulsator but also the inner tub only in a spin cycle that is performed after the wash water is drained out of the inner tub.
In addition, when the clutch is accurately shifted from the upper position to the lower position, the driving shaft of the motor cannot be accurately engaged with the inner tub. When the motor is driven with a high speed in this state, a shaft-engaging portion of the inner tub may be damaged. This results in the deterioration of the durability of the washing machine. Therefore, there is a need for a method for detecting if the clutch operates accurately and, when the clutch inaccurately operates, correcting the inaccurate operation of the clutch.